Heater control method and device

Abstract

The embodiment of the invention discloses a heater control method and device. The heater control method comprises the steps that when the working mode is a heating mode, the current temperature of cooling liquid at the water inlet end or the water outlet end of the air conditioning system is obtained; wherein the water outlet end is positioned between the switch valve and the heater; the water inlet end is located at the end, away from the switch valve, of the to-be-exchanged battery pack. The current heating requirement is calculated according to the current temperature of the cooling liquid at the water inlet end or the water outlet end and the corresponding set target temperature; and according to the current heating demand and the current opening number of the switch valves, the working state of the heater is controlled, and the heating capacity of the heater is made to be matched with the current heating demand. According to the technical scheme, when the heating requirement is calculated, the output of the heater is controlled in combination with the opening number of the switch valves, the heating capacity of the heater is matched with the required heat of the battery pack, then the battery pack can work at the proper temperature, and the situation that normal work and the service life of the battery pack are affected due to the fact that the output of the heater is too large or too small is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioning, and in particular to a heater control method and device. Background Art

[0002] In recent years, my country's new energy development trend has been rapid. The strategic goals of "carbon peak and carbon neutrality" have promoted the development of new energy vehicles. New energy heavy-duty trucks have also developed rapidly, and related battery swap stations have also developed accordingly.

[0003] When the battery cell temperature of the battery pack in the battery swap station is too high or too low, the battery life and performance will be greatly reduced, and the battery may even be damaged. Therefore, it is necessary to maintain an appropriate battery cell temperature to maintain the normal operation and life of the battery pack. The air conditioning system heats up or cools the battery pack to keep it in an appropriate battery cell temperature range.

[0004] However, the prior art has the problem that in the heating mode of the air-conditioning system, the heating capacity of the heater does not match the heating demand of the battery pack, which affects the normal operation and life of the battery pack. Summary of the invention

[0005] The present invention provides a heater control method and device to solve the problem that the heating amount of the heater does not match the heating demand of the battery pack.

[0006] According to one aspect of the present invention, a heater control method is provided, which is applied to an air conditioning system of a battery swap station, the air conditioning system includes a heating circuit, the heating circuit includes at least one switch valve and at least one heater, one end of the switch valve is connected to the heater, and the other end of the switch valve is connected to a battery pack to be heated; the working mode of the air conditioning system includes a heating mode; the heater control method includes:

[0007] When the working mode is heating mode, the current temperature of the coolant at the water inlet or outlet of the air conditioning system is obtained; wherein the water outlet is located between the switch valve and the heater; the water inlet is located at the end of the battery pack to be heated away from the switch valve;

[0008] Calculate the current heating demand based on the current temperature of the coolant at the water inlet or water outlet and the corresponding set target temperature;

[0009] According to the current heating demand and the current opening number of the switch valve, the working state of the heater is controlled so that the heating amount of the heater matches the current heating demand.

[0010] Optionally, the current heating demand is calculated according to the current temperature of the coolant at the water inlet or water outlet and the corresponding set target temperature, including:

[0011] Calculate the current heating demand according to the current inlet water temperature corresponding to the water inlet end, the first preset target temperature and the preset proportional band value;

[0012] Alternatively, the current heating demand is calculated according to the current outlet water temperature corresponding to the outlet water end, the second preset target temperature and the preset proportional band value.

[0013] Optionally, the number of switch valves is N, and the number of heaters is m; N and m are both integers greater than or equal to 1; according to the current heating demand and the current opening number of the switch valves, the working state of the heater is controlled so that the heating amount of the heater matches the current heating demand, including:

[0014] When the current heating demand is greater than or equal to the first percentage, the opening number of the switch valve is less than or equal to N / m, and one heater is controlled to be turned on.

[0015] Optionally, when the current heating demand is greater than or equal to the first percentage, and the opening number of the switch valve is less than or equal to N / m, controlling a heater to turn on includes:

[0016] When the number m of heaters is greater than or equal to 2, when the current heating demand is greater than or equal to the first percentage, the opening number of the switch valve is less than or equal to N / m, and a heater with the shortest cumulative operating time is controlled to be turned on.

[0017] Optionally, the number of switch valves is N, the number of heaters is m, and N is greater than or equal to m; according to the current heating demand and the current opening number of the switch valves, the working state of the heater is controlled so that the heating amount of the heater matches the current heating demand, and further includes:

[0018] When m is equal to 1, when it is detected that the current heating demand is less than or equal to the second percentage for a continuous first preset period of time, the heater is controlled to be turned off;

[0019] When m is equal to 1, the current heating demand is greater than the second percentage and less than the first percentage, and the heater is controlled to maintain the current state; wherein the second percentage is less than the first percentage;

[0020] When m is greater than or equal to 2, when it is detected that the current heating demand is less than the second percentage for a continuous first preset period of time, all heaters are controlled to be turned off in sequence at intervals of a preset time.

[0021] Optionally, the number of switch valves is N, and the number of heaters is m; m is greater than or equal to 2, and N is greater than or equal to m; and according to the current heating demand and the current opening number of the switch valves, the working state of the heater is controlled so that the heating amount of the heater matches the current heating demand, and further includes:

[0022] When the current heating demand is greater than or equal to the first percentage, and the number of openings of the switch valve is greater than N(m-1) / m, m heaters are controlled to be turned on;

[0023] When m is greater than 2, when the current heating demand is greater than or equal to the first percentage, and the number of openings of the switch valve is greater than N / m and less than or equal to N(m-1) / m, m-1 heaters are controlled to be turned on;

[0024] When the number of heaters currently turned on is greater than 1 and the number of switch valves turned on is less than or equal to N / m, keep 1 heater turned on and the other heaters turned off;

[0025] When the number of heaters currently turned on is greater than 1 and the number of switch valves turned on is greater than N / m and less than or equal to N(m-1) / m, keep m-1 heaters turned on and turn off the other heaters;

[0026] When the current heating demand is less than the third percentage, the current temperature change of the coolant at the water inlet or outlet within the first preset time period is greater than or equal to the first preset temperature, and the number of heaters turned on is greater than 1, control the heater with the longest cumulative running time to turn off.

[0027] Optionally, when m is greater than or equal to 3, when the current heating demand is less than a third percentage, the current temperature change of the coolant at the water inlet or the water outlet within the first preset time period is greater than or equal to the first preset temperature, and the number of heaters turned on is greater than 1, after controlling one heater with the longest cumulative running time to turn off, the method further includes:

[0028] The situation after the heater is turned off is continuously monitored. If the current heating demand is met again less than the third percentage after the first preset time period when the heater is turned off, the current temperature change of the coolant at the water inlet or outlet during the first preset time period is greater than or equal to the first preset temperature, and the number of heaters turned on is greater than 1, then control one heater to turn off, and continue monitoring until all heaters are turned off.

[0029] Optionally, the number of switch valves is N, and the number of heaters is m; m is greater than or equal to 2, and N is greater than or equal to m; and according to the current heating demand and the current opening number of the switch valves, the working state of the heater is controlled so that the heating amount of the heater matches the current heating demand, including:

[0030] When m is equal to 2, when the number of openings of the switch valve is greater than N(m-1) / m, and the number of openings of the heater is 1, if the current heating demand is detected to be greater than the fourth percentage for a second consecutive preset time period, another heater is controlled to be turned on;

[0031] When m is greater than 2, when the number of openings of the switch valve is greater than N / m and less than or equal to N(m-1) / m, and only one heater is turned on, if the current heating demand is detected to be greater than the fourth percentage for a second consecutive preset time period, the second heater is controlled to be turned on;

[0032] When m is greater than 2, when the number of switch valves opened is greater than N(m-1) / m, and the number of heaters opened is less than m-1, if it is detected for the second consecutive preset time period that the current heating demand is greater than the fourth percentage, one heater is controlled to be turned on; when m is greater than 2, when the number of switch valves opened is greater than N(m-1) / m, and the number of heaters opened is m-1, if it is detected for the second consecutive preset time period that the current heating demand is greater than the fifth percentage, the mth heater is controlled to be turned on.

[0033] Optionally, the heater control method also includes that when the number of heaters is set to m, if n heater failures occur, control is performed according to the number of heaters being mn, wherein n is greater than or equal to 1 and less than m.

[0034] According to another aspect of the present invention, there is provided a heater control device, the heater control device comprising:

[0035] The temperature acquisition module is used to obtain the current temperature of the coolant at the water inlet or outlet of the air conditioning system when the working mode is the heating mode; wherein the water outlet is located between the switch valve and the heater; and the water inlet is located at the end of the battery pack to be heated away from the switch valve;

[0036] A current heating demand calculation module is used to calculate the current heating demand according to the current temperature of the coolant at the water inlet or water outlet and the corresponding set target temperature;

[0037] The heater working state control module is used to control the working state of the heater according to the current heating demand and the current opening number of the switch valve, so that the heating amount of the heater matches the current heating demand.

[0038] The technical solution of the embodiment of the present invention is to obtain the current temperature of the coolant at the water inlet or outlet of the air-conditioning system when the air-conditioning system is in heating mode, calculate the current heating demand according to the current temperature of the coolant at the water inlet or outlet and the corresponding set target temperature, and control the working state of the heater according to the current heating demand and the current opening number of the switch valve, so that the heating amount of the heater matches the current heating demand, thereby allowing the battery pack to be heated to operate at an appropriate temperature, avoiding excessive or insufficient output of the heater to affect the normal operation and service life of the battery pack to be heated.

[0039] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0041] Figure 1 is a flow chart of a heater control method provided according to an embodiment of the present invention;

[0042] Figure 2 is a structural schematic diagram of an air conditioning system provided according to an embodiment of the present invention;

[0043] Figure 3 is a flow chart of another heater control method provided according to an embodiment of the present invention;

[0044] Figure 4 is a flow chart of another heater control method provided according to an embodiment of the present invention;

[0045] Figure 5 is a flow chart of another heater control method provided according to an embodiment of the present invention;

[0046] Figure 6 is a flow chart of another heater control method provided according to an embodiment of the present invention;

[0047] Figure 7 is a flow chart of another heater control method provided according to an embodiment of the present invention;

[0048] Figure 8 is a structural schematic diagram of a heater control device provided according to an embodiment of the present invention;

[0049] Figure 2 Among them, 1. water inlet temperature sensor; 2. expansion water tank; 3. water filter; 4. circulating water pump; 5. plate heat exchanger; 6. heater; 7. water outlet temperature sensor; 8. switch valve; 9. battery pack; 10. compressor; 11. condensing fan; 12. condenser; 13. electronic expansion valve. DETAILED DESCRIPTION

[0050] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0051] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0052] Figure 1 1 is a flow chart of a heater control method provided according to an embodiment of the present invention. The embodiment of the present invention can be applied to the control of a heater in an air conditioning system of a battery swap station. The heater control method can be executed by a heater control device, which can be implemented in the form of hardware and / or software. Figure 2 Schematic diagram of the structure of an air conditioning system provided according to an embodiment of the present invention. Figure 2 As shown, the heater control method is applied to the air-conditioning system of the battery swap station. The air-conditioning system includes a heating circuit. The heating circuit includes at least one switch valve 8 and at least one heater 6. One end of the switch valve 8 is connected to the heater 6, and the other end of the switch valve 8 is connected to the battery pack 9 to be heated. The working mode of the air-conditioning system includes a heating mode.

[0053] In the embodiment of the present invention, the air conditioning system includes an inlet water temperature sensor 1, an expansion water tank 2, a water filter 3, a circulating water pump 4, a plate heat exchanger 5, a heater 6, an outlet water temperature sensor 7, a switch valve 8, a battery pack 9, a compressor 10, a condensing fan 11, a condenser 12 and an electronic expansion valve 13. The connection relationship of each device is as follows: Figure 2As shown. The working modes of the air-conditioning system include a heating mode and a cooling mode. When the air-conditioning system is in the cooling mode, the working process of the refrigerant circuit of the air-conditioning system is as follows: the compressor 10 compresses the low-temperature and low-pressure gaseous refrigerant returned from the plate heat exchanger 5 into a high-temperature and high-pressure gaseous refrigerant, and the high-temperature and high-pressure gaseous refrigerant is discharged into the condenser 12 to be cooled into a high-temperature and high-pressure liquid refrigerant. The condensing fan 11 strengthens the heat exchange of the condenser 12. The high-temperature and high-pressure liquid refrigerant is throttled by the electronic expansion valve 13 and becomes a low-temperature and low-pressure gas-liquid mixed refrigerant, and then enters the plate heat exchanger 5 to exchange heat with the water-side coolant, becomes a low-temperature and low-pressure gaseous refrigerant, and then returns to the compressor 10. Circulation; The working process of the coolant circuit of the air-conditioning system is as follows: the circulating water pump 4 circulates the high-temperature coolant after the heat exchange in the battery pack 9 back to the expansion water tank 2, and the water inlet temperature sensor 1 on the main water inlet pipe can monitor the return water temperature in real time. The high-temperature coolant passes through the water filter 3 and is circulated and discharged by the circulating water pump 4 to the plate heat exchanger 5 for heat exchange with the low-temperature refrigerant on the refrigerant side, turning into low-temperature coolant, flowing through the heater 6, and the water outlet temperature sensor 7 on the main water outlet pipe can monitor the water outlet temperature in real time, and then flows through the switch valve 8, and finally flows into the battery pack 9 to exchange heat with it, and then circulates again.

[0054] When the air-conditioning system is in heating mode, the refrigerant circuit does not work, and the coolant circuit works as follows: the circulating water pump 4 circulates the low-temperature coolant after the heat exchange in the battery pack 9 back to the expansion water tank 2, and the water inlet temperature sensor 1 on the main water inlet pipe can monitor the return water temperature in real time. The low-temperature coolant passes through the water filter 3 and is circulated and discharged by the circulating water pump 4 through the plate heat exchanger 5, and then flows through the heater 6. The heater 6 heats the incoming low-temperature coolant into high-temperature coolant. The water outlet temperature sensor 7 on the main water outlet pipe can monitor the outlet water temperature in real time, and then flows through the switch valve 8, and finally flows into the battery pack 9 to exchange heat with it, and then circulates again.

[0055] like Figure 1 As shown, the heater control method includes:

[0056] S110. When the working mode is the heating mode, obtain the current temperature of the coolant at the water inlet or outlet of the air-conditioning system; wherein the water outlet is located between the switch valve and the heater; and the water inlet is located at the end of the battery pack to be heated away from the switch valve.

[0057] Specifically, refer to Figure 2, this heater control method is used when the air-conditioning system is in heating mode. The control mode of the heater can be selected as outlet water temperature control or inlet water temperature control. When outlet water temperature control is selected, the current temperature of the outlet water of the air-conditioning system is obtained through the outlet water temperature sensor 7; when inlet water temperature control is selected, the current temperature of the inlet water of the air-conditioning system is obtained through the inlet water temperature sensor 1. The outlet water is located between the switch valve 8 and the heater 6, and the temperature of the outlet water is obtained through the outlet water temperature sensor 7; the inlet water is located at the end of the battery pack 9 to be heated away from the switch valve 8, and between the battery pack 9 to be heated and the expansion water tank 2, and the temperature of the inlet water is obtained through the inlet water temperature sensor 1.

[0058] S120, calculating the current heating demand according to the current temperature of the coolant at the water inlet or water outlet and the corresponding set target temperature.

[0059] Specifically, refer to Figure 2 , S110 can obtain the current temperature of the coolant at the water inlet or water outlet of the air-conditioning system, and then calculate the current heating demand according to the corresponding set target temperature. The set target temperature is the target water outlet temperature of the air conditioner or the target water inlet temperature of the air conditioner. The set target temperature is set as a reference for temperature control, that is, the heating demand is calculated based on the difference between the actual measured temperature value and the corresponding set target temperature, and the heating amount of the heater is adjusted until the subsequent detected temperature value is close to or equal to the set target temperature. The difference between the set target temperature and the current temperature of the coolant at the water inlet is positively correlated with the current heating demand, or the difference between the set target temperature and the current temperature of the coolant at the water outlet is positively correlated with the current heating demand. The calculation method of the current heating demand can be equal to the difference between the set target temperature and the current temperature of the coolant at the water inlet or water outlet, or the difference can be further calculated and processed, such as the ratio of the difference to a constant.

[0060] S130. According to the current heating demand and the current opening number of the switch valve, the working state of the heater is controlled so that the heating amount of the heater matches the current heating demand.

[0061] In an optional embodiment, the operating state of the heater includes on and off. In another optional embodiment, the operating state of the heater also includes the heating power in the on state.

[0062] Specifically, refer to Figure 2, the switch valve 8 is a solenoid valve for the water circuit at the end of the air-conditioning system, which is connected to the battery pack 9. The total number of switch valves 8 can be set to N, and the value of N can be an integer greater than or equal to 1. The switch command of the switch valve 8 is issued to the air-conditioning system by the station control system of the battery swap station. The conventional configuration number of heaters 6 in the air-conditioning system is 1-3, and can also be set to be greater than 3, which is not specifically limited here. Optionally, at least two heating demand intervals are preset, and the working state of the heater is controlled according to the heating interval to which the current heating demand belongs and the current opening number of the switch valve. When the number of heaters 6 is one, the heating amount is controlled by controlling the opening or closing of one heater 6, or the heating power of one heater 6. When the number of heaters 6 is at least two, the number of heaters 6 in operation can be controlled by controlling the opening and closing of the heaters 6, and / or the heating power of the heaters 6, thereby controlling the heating amount.

[0063] According to the calculated current heating demand and the current opening number of the switch valves, the working state of the heater 6 is controlled so that the heating amount of the heater 6 matches the current heating demand. For example, when the current heating demand is greater than or equal to 100%, the heater 6 needs to be turned on. When the number of heaters 6 is large, the opening number of the heaters 6 is determined according to the opening number of the switch valves 8. For example, if the opening number of the switch valves 8 is less than half of the total number of the switch valves, the heating demand is small at this time, and one heater 6 can be controlled to be turned on first; if the opening number of the switch valves 8 is greater than half of the total number of the switch valves, the heating demand becomes large at this time, and one more heater 6 can be controlled to be turned on to meet the heating demand.

[0064] Optionally, when the number of switch valves 8 opened is certain, the number of heaters 6 opened is positively correlated with the current heating demand, so as to avoid the increase of energy consumption caused by the heating amount provided by the heater 6 being greater than the current heating demand, and to avoid the heating amount provided by the heater 6 being less than the current heating demand and failing to achieve the purpose of heating.

[0065] In the air conditioning system, generally, the heater 6 can be turned on only after the circulating water pump 4 is turned on for a period of time. For example, the heater 6 can be turned on only after the circulating water pump 4 is turned on for 30 seconds. When the control output of the circulating water pump 4 is 0%, all heaters 6 should be controlled to be turned off immediately. Since the speed is 0 when the output of the circulating water pump 4 is 0%, the coolant stops circulating, and all heaters 6 are turned off to prevent heating overload.

[0066] The technical solution of the embodiment of the present invention is that when the air-conditioning system is in heating mode, the current temperature of the coolant at the water inlet or outlet of the air-conditioning system is obtained, the current heating demand is calculated according to the current temperature of the coolant at the water inlet or outlet and the corresponding set target temperature, and the working state of the heater is controlled according to the current heating demand and the current opening number of the switch valve 8, so that the heating amount of the heater 6 matches the current heating demand, so that the battery pack 9 to be heated can operate at an appropriate temperature, avoiding excessive or insufficient output of the heater 6 to affect the normal operation and service life of the battery pack 9 to be heated.

[0067] Figure 3 FIG. 1 is a flow chart of another heater control method provided according to an embodiment of the present invention. Figure 3 As shown, the heater control method includes:

[0068] S210. When the working mode is the heating mode, obtain the current temperature of the coolant at the water inlet or outlet of the air-conditioning system; wherein the water outlet is located between the switch valve and the heater; and the water inlet is located at the end of the battery pack to be heated away from the switch valve.

[0069] S220, calculating the current heating demand according to the current inlet water temperature corresponding to the water inlet, the first preset target temperature and the preset proportional band value; or calculating the current heating demand according to the current outlet water temperature corresponding to the water outlet, the second preset target temperature and the preset proportional band value.

[0070] When the control mode is selected as water inlet temperature control, the current heating demand is calculated according to the current water inlet temperature corresponding to the water inlet end, the first preset target temperature and the preset proportional band value. Exemplarily, the current water inlet temperature corresponding to the water inlet end is represented by T1, and the current water inlet temperature corresponding to the water inlet end is measured by the water inlet temperature sensor; the first preset target temperature can be represented by Tsh_1, and the first preset target temperature is the target water inlet temperature of the air conditioning system set in the heating mode; the preset proportional band value can be represented by △Th, which can be adjusted according to the difference between the first preset target temperature and the current water inlet temperature corresponding to the water inlet end. Exemplarily, the preset proportional band value is positively correlated with the difference between the first preset target temperature and the current water inlet temperature corresponding to the water inlet end. The current heating demand can be represented by CHC, CHC = (Tsh_1-T1) / △Th*100%.

[0071] When the control mode is selected as the outlet water temperature control, the current heating demand is calculated according to the current outlet water temperature corresponding to the outlet water end, the second preset target temperature and the preset proportional band value. Exemplarily, the current outlet water temperature corresponding to the outlet water end is represented by T2, and the current outlet water temperature corresponding to the outlet water end is measured by the outlet water temperature sensor; the second preset target temperature can be represented by Tsh_2, and the second preset target temperature is the target outlet water temperature of the air conditioning system set in the heating mode; the preset proportional band value can be represented by △Th, and can be adjusted according to the difference between the second preset target temperature and the current outlet water temperature corresponding to the outlet water end, for example, the preset proportional band value can be set to 2. The current heating demand can be represented by CHC, CHC = (Tsh_2-T2) / △Th*100%.

[0072] S230: Control the working state of the heater according to the current heating demand and the current opening number of the switch valve, so that the heating amount of the heater matches the current heating demand.

[0073] Figure 4 FIG. 1 is a flow chart of another heater control method provided according to an embodiment of the present invention. Figure 4 As shown, the heater control method includes:

[0074] S310. When the working mode is the heating mode, obtain the current temperature of the coolant at the water inlet or outlet of the air-conditioning system; wherein the water outlet is located between the switch valve and the heater; and the water inlet is located at the end of the battery pack to be heated away from the switch valve.

[0075] S320: Calculate the current heating demand according to the current temperature of the coolant at the water inlet or water outlet and the corresponding set target temperature.

[0076] S330: When the current heating demand is greater than or equal to the first percentage and the opening number of the switch valve is less than or equal to N / m, a heater is controlled to be turned on.

[0077] Specifically, the number of switch valves is N, and the number of heaters is m; N and m are both integers greater than or equal to 1. The first percentage may be 100%. When the current heating demand is ≥100%, the air conditioning system is determined to be in heating mode, and the working state of the heater is controlled. Exemplarily, in the heating mode, when the number of heaters m=1, if the current heating demand is ≥100%, and the number of switch valves opened is less than or equal to N, the heater is controlled to be turned on.

[0078] Based on the technical solution of the embodiment of the present invention, optionally, when the number of heaters m is greater than or equal to 2, when the current heating demand is greater than or equal to the first percentage, the number of switch valves opened is less than or equal to N / m, and a heater with the shortest cumulative operating time is controlled to turn on.

[0079] Exemplarily, in the heating mode, when the number of heaters m=2, if the current heating demand is ≥100%, and the number of switch valves opened is less than or equal to N / 2, only one heater with the shortest cumulative running time is turned on. Turning on only one heater with the shortest cumulative running time can balance the running time of the heaters, increase the service life of the heaters, and reduce the loss of the heaters. The cumulative running time of the heaters is detected by the controller. If a decimal point appears when calculating N / 2, round it up. For example, if N=25, then N / 2=12.5, which is taken as 13. This rounding principle applies to any embodiment of the present invention.

[0080] For example, in heating mode, when the number of heaters m=3, if the current heating demand is ≥100% and the number of switch valves opened is less than or equal to N / 3, only one heater with the shortest cumulative operating time is opened.

[0081] Figure 5 FIG. 1 is a flow chart of another heater control method provided according to an embodiment of the present invention. Figure 5 As shown, the heater control method includes:

[0082] S410. When the working mode is the heating mode, obtain the current temperature of the coolant at the water inlet or outlet of the air-conditioning system; wherein the water outlet is located between the switch valve and the heater; and the water inlet is located at the end of the battery pack to be heated away from the switch valve.

[0083] S420: Calculate the current heating demand according to the current temperature of the coolant at the water inlet or water outlet and the corresponding set target temperature.

[0084] The number of the switch valves is N, the number of the heaters is m, and N is greater than or equal to m.

[0085] S430, when m is equal to 1, when it is detected that the current heating demand is less than or equal to the second percentage for a continuous first preset time period, the heater is controlled to be turned off.

[0086] Specifically, the first preset time period can be set to 30 seconds. The second percentage can be set to -20%. For example, in the heating mode, when the number of heaters in the air-conditioning system m=1, if the current heating demand is detected to be ≤-20% for 30 consecutive seconds, it means that the current heating demand is very low, and the heater can be controlled to be turned off.

[0087] S440, when m is equal to 1, the current heating demand is greater than the second percentage and less than the first percentage, and the heater is controlled to maintain the current state; wherein the second percentage is less than the first percentage.

[0088] For example, when the number of heaters in the air conditioning system is m=1, if -20%<current heating demand<100%, it means that the heating demand does not change much, and the heater can maintain the current state. For example, the heater is off at the 10th second, and it is detected at the 11th second that -20%<current heating demand<100%, no other action is required, and the heater only needs to maintain the current state.

[0089] S450 , when m is greater than or equal to 2, when it is detected that the current heating demand is less than the second percentage for a continuous first preset period of time, all heaters are controlled to be turned off in sequence at intervals of a preset time.

[0090] Specifically, the preset time is a preset interval time for controlling the heater to shut down. Exemplarily, the preset time can be set to 5S. In heating mode, when the number of heaters set is ≥2, if the current heating demand is detected to be <-20% for 30 consecutive seconds, it means that the current heating demand is very low, and all heaters can be controlled to shut down in sequence at intervals of 5S. In order to prevent the heaters from being frequently started and stopped, any heater needs to meet the minimum shutdown time of 60S before it can be turned on again. When the air-conditioning system receives the request to exit the heating mode, all heaters need to be shut down in sequence at intervals of 5S.

[0091] Figure 6 FIG. 1 is a flow chart of another heater control method provided according to an embodiment of the present invention. Figure 6 As shown, the heater control method includes:

[0092] S510. When the working mode is the heating mode, obtain the current temperature of the coolant at the water inlet or outlet of the air-conditioning system; wherein the water outlet is located between the switch valve and the heater; and the water inlet is located at the end of the battery pack to be heated away from the switch valve.

[0093] S520: Calculate the current heating demand according to the current temperature of the coolant at the water inlet or water outlet and the corresponding set target temperature.

[0094] The number of the switch valves is N, the number of the heaters is m, m is greater than or equal to 2, and N is greater than or equal to m.

[0095] S530: When the current heating demand is greater than or equal to the first percentage, and the number of open switch valves is greater than N(m-1) / m, control m heaters to be turned on.

[0096] For example, when the number of heaters set is m=2, if the current heating demand is ≥100%, and the number of switch valves opened is >N / 2, both heaters are controlled to be turned on.

[0097] For example, when the number of heaters set is m=3, if the current heating demand is ≥100%, and the number of switch valves opened is >2N / 3, all three heaters are controlled to be turned on.

[0098] S540, when m is greater than 2, when the current heating demand is greater than or equal to the first percentage, and the opening number of the switch valve is greater than N / m and less than or equal to N(m-1) / m, m-1 heaters are controlled to be turned on.

[0099] For example, when the number of heaters set is m=3, if the current heating demand is ≥100%, and N / 3<the number of switch valves opened≤2N / 3, then two heaters with the shortest cumulative running time are opened according to the running time balance principle.

[0100] When the number of heaters set is greater than 1, if the heater needs to be turned on, the heater with a shorter running time will be turned on first according to the running time balance principle, and another heater will be turned on at least 5S later; if the heater needs to be turned off, the heater with a longer running time will be turned off first according to the running time balance principle, and another heater will be turned off at least 5S later.

[0101] S550: When the number of heaters currently turned on is greater than one and the number of switch valves turned on is less than or equal to N / m, keep one heater turned on and the other heaters turned off.

[0102] For example, if the number of heaters currently turned on is 2, and the number of switch valves turned on is ≤ N / 2, only one heater with a short cumulative operating time is kept turned on, and one heater with a long cumulative operating time is turned off.

[0103] For example, if the number of heaters currently turned on is 3, and the number of on-off valves turned on is ≤ N / 3, only the heater with the shortest cumulative operating time is left turned on, and the remaining heaters are turned off.

[0104] S560: When the number of heaters currently turned on is greater than 1 and the number of switch valves turned on is greater than N / m and less than or equal to N(m-1) / m, keep m-1 heaters turned on and the other heaters turned off.

[0105] For example, if the number of heaters currently turned on is 3, and N / 3<the number of switch valves turned on≤2N / 3, only the two heaters with the shortest cumulative operating time are left turned on, and the remaining heaters are turned off.

[0106] S570: When the current heating demand is less than the third percentage, the current temperature change of the coolant at the water inlet or outlet within the first preset time period is greater than or equal to the first preset temperature, and the number of heaters turned on is greater than 1, control one heater with the longest cumulative running time to turn off.

[0107] Specifically, the third percentage may be 0%. The first preset temperature is a preset change in the current temperature of the coolant at the water inlet or the water outlet. Exemplarily, the first preset temperature is 0.1°C.

[0108] For example, when the number of heaters set is m=2, if it is detected that the current heating demand is less than 0%, the current temperature change of the coolant at the water inlet or outlet within 30S is ≥0.1°C, and the number of heaters turned on is 2, then the heater with the longest cumulative running time is turned off. The heater is controlled to operate only when the three conditions are met at the same time, in order to reduce the error caused by the fluctuation of the air conditioning system and improve the control accuracy.

[0109] On the basis of the technical solution of the above-mentioned invention embodiment, optionally, when m is greater than or equal to 3, when the current heating demand is less than a third percentage, the current temperature change of the coolant at the water inlet or the water outlet within the first preset time period is greater than or equal to the first preset temperature, and the number of heaters turned on is greater than 1, after controlling a heater with the longest cumulative running time to turn off, continuously monitor the situation after the heater is turned off, if after the first preset time period when the heater is turned off, the current heating demand is less than the third percentage, the current temperature change of the coolant at the water inlet or the water outlet within the first preset time period is greater than or equal to the first preset temperature, and the number of heaters turned on is greater than 1, control another heater to turn off, and continue monitoring until all heaters are turned off.

[0110] For example, when the number of heaters set is m=3, if it is detected that the current heating demand is less than 0%, the current temperature change of the coolant at the water inlet or outlet within 30S is ≥0.1°C, and the number of heaters turned on is >1, then turn off the heater with the longest cumulative running time. After turning off the heater with the longest cumulative running time, continue to monitor the situation after the heater is turned off. If the condition of "the current heating demand is detected to be less than 0%, the current temperature change of the coolant at the water inlet or outlet within 30S is ≥0.1°C, and the number of heaters turned on is >1" is met again after 30S, turn off the heater with the longest cumulative running time again, and continue to monitor until all heaters are turned off.

[0111] Figure 7 FIG. 1 is a flow chart of another heater control method provided according to an embodiment of the present invention. Figure 7 As shown, the heater control method includes:

[0112] S610. When the working mode is the heating mode, obtain the current temperature of the coolant at the water inlet or outlet of the air-conditioning system; wherein the water outlet is located between the switch valve and the heater; and the water inlet is located at the end of the battery pack to be heated away from the switch valve.

[0113] S620: Calculate the current heating demand according to the current temperature of the coolant at the water inlet or water outlet and the corresponding set target temperature.

[0114] The number of the switch valves is N, the number of the heaters is m, m is greater than or equal to 2, and N is greater than or equal to m.

[0115] S630, when m is equal to 2, when the number of switch valves opened is greater than N(m-1) / m, and the number of heaters opened is 1, if the current heating demand is detected to be greater than the fourth percentage for a second consecutive preset time period, another heater is controlled to open.

[0116] Specifically, the second preset time period is different from the first preset time period, and the second preset time period can be set to 60S. The fourth percentage can be 50%. The number of heaters set is m=2. When the number of switch valves opened is greater than N / 2 and one heater is already in the open state, if the current heating demand is detected to be greater than 50% for 60 consecutive seconds, another heater is turned on.

[0117] S640, when m is greater than 2, when the number of openings of the switch valve is greater than N / m and less than or equal to N(m-1) / m, and only one heater is turned on, if the current heating demand is detected to be greater than the fourth percentage for the second consecutive preset time period, the second heater is controlled to turn on.

[0118] Exemplarily, the number of heaters set is m=3. When N / 3<the number of switch valves opened≤2N / 3 and only one heater with a short cumulative running time is currently in the on state, if the current heating demand is detected to be greater than 50% for 60 consecutive seconds, the second heater with a short cumulative running time is controlled to be turned on.

[0119] S650, when m is greater than 2, when the number of switch valves opened is greater than N(m-1) / m, and the number of heaters opened is less than m-1, if it is detected for the second consecutive preset time period that the current heating demand is greater than the fourth percentage, one heater is controlled to be turned on; when m is greater than 2, when the number of switch valves opened is greater than N(m-1) / m, and the number of heaters opened is m-1, if it is detected for the second consecutive preset time period that the current heating demand is greater than the fifth percentage, the mth heater is controlled to be turned on.

[0120] The fifth percentage may be 34%. For example, the number of heaters set is m=3, when the number of switch valves opened is greater than 2N / 3, and the number of heaters opened is less than 2, if the current heating demand is detected to be greater than 50% for 60 consecutive seconds, a heater with a short cumulative running time is controlled to be turned on.

[0121] Exemplarily, the number of heaters set is m=3. If the number of heaters currently turned on is 2, and the current heating demand is detected to be greater than 34% for 60 consecutive seconds, the third heater is turned on.

[0122] Based on the technical solution of the above-mentioned invention embodiment, optionally, when the number of heaters is set to m, if n heater failures occur, control is performed according to the number of heaters being mn, where n is greater than or equal to 1 and less than m.

[0123] In the embodiment of the present invention, exemplarily, when the number of heaters set is m=3, if one heater fails, control is performed according to the conditions when the number of heaters set is m=2; if two heaters fail, control is performed according to the conditions when the number of heaters set is m=1.

[0124] Exemplarily, when the number of heaters set is m=2, if one heater fails, control is performed according to the conditions when the number of heaters set is m=1.

[0125] Figure 8 Schematic diagram of a heater control device according to an embodiment of the present invention. Figure 8 As shown, the heater control device includes:

[0126] The temperature acquisition module 100 is used to obtain the current temperature of the coolant at the water inlet or outlet of the air-conditioning system when the working mode is the heating mode; wherein the water outlet is located between the switch valve and the heater; the water inlet is located at the end of the battery pack to be heated away from the switch valve.

[0127] Specifically, refer to Figure 2 The heater control device is used when the air conditioning system is in heating mode. The heater control mode can be selected as outlet water temperature control or inlet water temperature control. When outlet water temperature control is selected, the current temperature of the outlet water end of the air conditioning system is obtained through the outlet water temperature sensor 7 of the temperature acquisition module 100; when inlet water temperature control is selected, the current temperature of the inlet water end of the air conditioning system is obtained through the inlet water temperature sensor 1 of the temperature acquisition module 100.

[0128] The current heating demand calculation module 200 is used to calculate the current heating demand according to the current temperature of the coolant at the water inlet or water outlet and the corresponding set target temperature.

[0129] Specifically, the temperature acquisition module 100 can acquire the current temperature of the coolant at the water inlet or outlet of the air conditioning system, and then calculate the current heating demand according to the corresponding set target temperature through the current heating demand calculation module 200. Exemplarily, the set target temperature of the coolant at the water outlet in the heating mode is subtracted from the current temperature of the coolant detected by the water outlet temperature sensor, and the difference is compared with the proportional band value to obtain the current heating demand.

[0130] The heater working state control module 300 is used to control the working state of the heater according to the current heating demand and the current opening number of the switch valve, so that the heating amount of the heater matches the current heating demand.

[0131] According to the technical solution of the embodiment of the present invention, when the air-conditioning system is in heating mode, the current temperature of the coolant at the water inlet or outlet of the air-conditioning system is obtained through the temperature acquisition module 100, and the current heating demand calculation module 200 is applied to calculate the current heating demand according to the current temperature of the coolant at the water inlet or outlet and the corresponding set target temperature, and the heater working state control module 300 is used to control the working state of the heater according to the current heating demand and the current opening number of the switch valve, so that the heating amount of the heater matches the current heating demand, so that the battery pack to be heated can operate at an appropriate temperature, thereby avoiding excessive or insufficient heater output affecting the normal operation and service life of the battery pack to be heated.

[0132] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0133] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A heater control method, characterized in that: An air conditioning system applied to a battery swap station, the air conditioning system comprising a heating circuit, the heating circuit comprising at least one switch valve and at least one heater, one end of the switch valve being connected to the heater, and the other end of the switch valve being connected to a battery pack to be heated; the working mode of the air conditioning system comprising a heating mode; the heater control method comprising: When the working mode is the heating mode, the current temperature of the coolant at the water inlet or water outlet of the air conditioning system is obtained; wherein the water outlet is located between the switch valve and the heater; and the water inlet is located at the end of the battery pack to be heated away from the switch valve; Calculating the current heating demand according to the current temperature of the coolant at the water inlet or the water outlet and the corresponding set target temperature; According to the current heating demand and the current opening number of the switch valve, the working state of the heater is controlled so that the heating amount of the heater matches the current heating demand.

2. The heater control method according to claim 1, characterized in that: The calculating the current heating demand according to the current temperature of the coolant at the water inlet or the water outlet and the corresponding set target temperature includes: Calculating a current heating demand according to a current water inlet temperature corresponding to the water inlet end, a first preset target temperature, and a preset proportional band value; Alternatively, the current heating demand is calculated according to the current outlet water temperature corresponding to the outlet water end, the second preset target temperature and the preset proportional band value.

3. The heater control method according to claim 1, characterized in that: The number of the switch valves is N, and the number of the heaters is m; N and m are both integers greater than or equal to 1; and the operating state of the heater is controlled according to the current heating demand and the current opening number of the switch valves so that the heating amount of the heater matches the current heating demand, including: When the current heating demand is greater than or equal to the first percentage, the opening number of the switch valve is less than or equal to N / m, and one of the heaters is controlled to be turned on.

4. The heater control method according to claim 3, characterized in that: When the current heating demand is greater than or equal to the first percentage, the opening number of the switch valve is less than or equal to N / m, and one of the heaters is controlled to be turned on, comprising: When the number m of the heaters is greater than or equal to 2, when the current heating demand is greater than or equal to the first percentage, the opening number of the switch valve is less than or equal to N / m, and a heater with the shortest cumulative operating time is controlled to be turned on.

5. The heater control method according to claim 1, characterized in that: The number of the switch valves is N, the number of the heaters is m, and N is greater than or equal to m; the working state of the heater is controlled according to the current heating demand and the current opening number of the switch valves so that the heating amount of the heater matches the current heating demand, and further includes: When m is equal to 1, when it is detected that the current heating demand is less than or equal to the second percentage for a continuous first preset period of time, the heater is controlled to be turned off; When m is equal to 1, the current heating demand is greater than the second percentage and less than the first percentage, and the heater is controlled to maintain the current state; wherein the second percentage is less than the first percentage; When m is greater than or equal to 2, when it is detected that the current heating demand is less than the second percentage for a continuous first preset period of time, all the heaters are controlled to be turned off in sequence at intervals of a preset time.

6. The heater control method according to claim 1, characterized in that: The number of the switch valves is N, the number of the heaters is m; m is greater than or equal to 2, and N is greater than or equal to m; the working state of the heater is controlled according to the current heating demand and the current opening number of the switch valves so that the heating amount of the heater matches the current heating demand, and further includes: When the current heating demand is greater than or equal to the first percentage, and the number of openings of the switch valve is greater than N(m-1) / m, controlling m of the heaters to be turned on; When m is greater than 2, when the current heating demand is greater than or equal to the first percentage, and the opening number of the switch valve is greater than N / m and less than or equal to N(m-1) / m, m-1 of the heaters are controlled to be turned on; When the number of the heaters currently turned on is greater than one and the number of the switch valves turned on is less than or equal to N / m, one of the heaters is kept turned on and the other heaters are turned off; When the number of the heaters currently turned on is greater than 1 and the number of the switch valves turned on is greater than N / m and less than or equal to N(m-1) / m, keep m-1 of the heaters turned on and turn off the other heaters; When the current heating demand is less than the third percentage, the current temperature change of the coolant at the water inlet or the water outlet within the first preset time period is greater than or equal to the first preset temperature, and the number of heaters turned on is greater than 1, the heater with the longest cumulative running time is controlled to be turned off.

7. The heater control method according to claim 6, characterized in that: When m is greater than or equal to 3, after controlling one of the heaters with the longest cumulative running time to be turned off when the current heating demand is less than the third percentage, the current temperature change of the coolant at the water inlet or the water outlet within the first preset time period is greater than or equal to the first preset temperature, and the number of heaters turned on is greater than 1, the method further includes: The situation after the heater is turned off is continuously monitored. If the current heating demand is met again less than the third percentage after the first preset time period when the heater is turned off, the current temperature change of the coolant at the water inlet or the water outlet within the first preset time period is greater than or equal to the first preset temperature, and the number of heaters turned on is greater than 1, then control one of the heaters to turn off, and continue monitoring until all the heaters are turned off.

8. The heater control method according to claim 1, characterized in that: The number of the switch valves is N, the number of the heaters is m; m is greater than or equal to 2, and N is greater than or equal to m; and the operating state of the heater is controlled according to the current heating demand and the current opening number of the switch valves so that the heating amount of the heater matches the current heating demand, including: When m is equal to 2, when the number of openings of the switch valve is greater than N(m-1) / m, and the number of openings of the heater is 1, if it is detected that the current heating demand is greater than the fourth percentage for a second consecutive preset time period, another of the heaters is controlled to be turned on; When m is greater than 2, when the number of openings of the switch valve is greater than N / m and less than or equal to N(m-1) / m, and only one of the heaters is turned on, if it is detected that the current heating demand is greater than the fourth percentage for a second consecutive preset time period, the second heater is controlled to be turned on; When m is greater than 2, when the number of openings of the switch valve is greater than N(m-1) / m, and the number of openings of the heater is less than m-1, if it is detected that the current heating demand is greater than the fourth percentage for the second consecutive preset time period, one of the heaters is controlled to be turned on; when m is greater than 2, when the number of openings of the switch valve is greater than N(m-1) / m, and the number of openings of the heater is m-1, if it is detected that the current heating demand is greater than the fifth percentage for the second consecutive preset time period, the mth heater is controlled to be turned on.

9. The heater control method according to claim 1, characterized in that: It also includes that when the number of the heaters is set to m, if n heater failures occur, control is performed according to the number of the heaters being mn, wherein n is greater than or equal to 1 and less than m.

10. A heater control device, characterized in that: include: The temperature acquisition module is used to acquire the current temperature of the coolant at the water inlet or water outlet of the air conditioning system when the working mode is the heating mode; wherein the water outlet is located between the switch valve and the heater; and the water inlet is located at the end of the battery pack to be heated away from the switch valve; A current heating demand calculation module, used to calculate the current heating demand according to the current temperature of the coolant at the water inlet or the water outlet and the corresponding set target temperature; The heater working state control module is used to control the working state of the heater according to the current heating demand and the current opening number of the switch valve, so that the heating amount of the heater matches the current heating demand.

Images